HbA1c
Information Fact Sheet
What is Hemoglobin A1c?
Hemoglobin (Hb) is the compound in the red blood cells that transports oxygen. One of the types of hemoglobin (Hb) is called HbA; HbA1c is a specific subtype of HbA. Glucose binds slowly to Hb and produces glycosylated Hb. There are several types of glycosylated hemoglobin measures (including total glycosylated Hb and HbA1), but HbA1c, which is formed when HbA is glycosylated, is now considered the best and standard measure.
The higher the blood sugar, the faster HbA1c will be formed, resulting in higher HbA1c levels. Red blood cells circulate 60-120 days, and the HbA1c level is in part affected by blood sugar levels over a three-month period. However, it is heavily weighted to levels over the past 45-60 days.
Why is HbA1c important?
It is a simple way to evaluate average glucose levels over the past two to four weeks.
It is the best single test for evaluating the risk for glycemic damage to tissues (e.g., nerves, and small blood vessels in the eyes and kidneys) and, thus, risk of complications of diabetes.
Clinical trials, such as the Diabetes Control and Complications Trial (DCCT) and the United Kingdom Prospective Diabetes Study (UKPDS) have shown that improving HbA1c measures will decrease the development and progression of eye, kidney and nerve complications in both type 1 and type 2 diabetes.
What do the test results mean?
The HbA1c is linearly related to the average blood sugar over the past 1-3 months
The HbA1c is strongly associated with the risk of development and progression of microvascular and nerve complications.
Since these complications occur slowly over time, the younger you are when you get diabetes (or the longer your life expectancy), the higher the risk of end-stage complications.
High HbA1c (>9.0-9.5%) is associated with very rapid progression of microvascular complications.
Additional information on interpretation of HbA1c values and recommendations can be found in "Clinical
What is Hemoglobin A1c?
Hemoglobin (Hb) is the compound in the red blood cells that transports oxygen. One of the types of hemoglobin (Hb) is called HbA; HbA1c is a specific subtype of HbA. Glucose binds slowly to Hb and produces glycosylated Hb. There are several types of glycosylated hemoglobin measures (including total glycosylated Hb and HbA1), but HbA1c, which is formed when HbA is glycosylated, is now considered the best and standard measure.
The higher the blood sugar, the faster HbA1c will be formed, resulting in higher HbA1c levels. Red blood cells circulate 60-120 days, and the HbA1c level is in part affected by blood sugar levels over a three-month period. However, it is heavily weighted to levels over the past 45-60 days.
Why is HbA1c important?
It is a simple way to evaluate average glucose levels over the past two to four weeks.
It is the best single test for evaluating the risk for glycemic damage to tissues (e.g., nerves, and small blood vessels in the eyes and kidneys) and, thus, risk of complications of diabetes.
Clinical trials, such as the Diabetes Control and Complications Trial (DCCT) and the United Kingdom Prospective Diabetes Study (UKPDS) have shown that improving HbA1c measures will decrease the development and progression of eye, kidney and nerve complications in both type 1 and type 2 diabetes.
What do the test results mean?
The HbA1c is linearly related to the average blood sugar over the past 1-3 months
The HbA1c is strongly associated with the risk of development and progression of microvascular and nerve complications.
Since these complications occur slowly over time, the younger you are when you get diabetes (or the longer your life expectancy), the higher the risk of end-stage complications.
High HbA1c (>9.0-9.5%) is associated with very rapid progression of microvascular complications.
Additional information on interpretation of HbA1c values and recommendations can be found in "Clinical